Externalization of Speech When Listening With Hearing Aids.

The study included only young adults, so it does not show what happens in older adults who commonly use hearing aids. Participants were tested immediately after fitting, so the results describe acute effects rather than effects after weeks or months of use. The room was a sound booth with little reverberation, so distance judgments were driven partly by loudness rather than real-world spatial cues. Head movement was not controlled or recorded, so natural head motion in daily life could change the effects. Only 6 of the 10 hearing-impaired listeners completed the own-aids condition, and their devices and settings differed, so own-device results are limited. Hearing-impaired listeners did not complete the in-the-ear open condition because the manufacturer did not recommend it for greater than mild losses. For in-the-ear conditions, devices could mix in-the-ear and behind-the-ear microphone inputs depending on calibration and gain, so the two microphone positions were not fully independent. Ear-canal recordings were made in a manikin, not in each listener, so individual acoustic differences were not measured.

The paper states that the National Institute on Deafness and Other Communication Disorders funded the work.

Do not conclude that hearing aids should be avoided or that these laboratory effects are the same in daily life. The study tested acute judgments in young adults, not long-term users in real environments.